A few days ago, Ramesh Ferris took his first ride on a motorbike. Born in India and raised in Canada, Ferris made the journey into rural India to meet Ruksa Khatun, the 3-year-old girl who is the last child in India known to have contracted polio. This weekend, as the nation quietly marked two years without a single infection by the wild poliovirus, that child’s parents wondered how they were going to manage the surgery her doctors say she needs on a foot crippled by the disease.

Ferris would understand the gravity of their situation better than most. After he was paralyzed by polio as an infant, his birth mother was unable to provide him with the care he needed and placed him in an international orphanage. He was adopted by a family in Canada’s Yukon territory, where he grew up, eventually becoming an advocate in the global drive to end polio. India was once considered the center of the crippling disease — and was expected to be the last place it would be eradicated. But last year, the World Health Organization (WHO) confirmed that polio was no longer endemic in India. Next year, if no new cases arise, the country will be declared polio-free, perhaps the greatest public-health feat it has ever achieved, saving hundreds of thousands of children from paralysis and death.

India’s accomplishment was a triumph of consistent and strong political will as well as international coordination and has given a huge lift to the global fight against polio, a disease that as recently as 1988 claimed 350,000 people each year. In 2012, the global caseload was just 222. When India came off the WHO list last year, the number of countries where the virus is still endemic came down to three: Nigeria, Pakistan and Afghanistan. “Given India’s complex circumstances in terms of where people live and its topography, it’s astounding it came off the list before other countries,” says Ferris.

(Read TIME’s cover story on how geopolitics may threaten the global effort to fight polio.)

Understanding how a country so huge, so diverse and so poor managed to stop polio transmission offers important lessons both for the complicated international effort to eradicate the disease for good and for India’s own health care system. The oral polio vaccine was introduced in India in 1978, a year before the U.S. was declared polio-free. In 1985, Rotary International launched its global effort to end polio everywhere. India was a signatory to the 1988 WHO treaty committing participating nations to be part of that effort. But on the ground in India, “there was not much happening,” says Dr. Naveen Thacker, a past president of the Indian Academy of Pediatrics and a member of the expert advisory group to the Indian government for polio eradication.

It wasn’t until 1994, when the local government of the New Delhi capital region conducted a hugely successful mass immunization campaign targeting children, that the idea began to gain momentum that India might actually be able to tackle this disease. Though other Indian states like Kerala and Tamil Nadu had conducted similar campaigns before, it wasn’t until the national government saw tangible progress that officials were sufficiently convinced they could make a difference.“That’s when India decided to go after polio in a big way,” says Thacker. Routine immunization — in which patients sought out the vaccine themselves — had reduced polio but couldn’t stop it from spreading. Reported immunization coverage across India was officially as high as 90%, but the disease was still being transmitted.

In 1995 and ’96, the government started to organize annual national immunization days, and in 1997, India established the National Polio Surveillance Project. In 1999, it set up an expert advisory group that monitored the program and provided continuous evaluation of how the disease was behaving around the country. Eventually, that group, which Thacker was a part of, decided the best way to fight the disease was to focus on the states of Uttar Pradesh and Bihar, two of the poorest areas in the country where polio transmission was uninterrupted. Crucially, the group also decided to target migrant workers moving in and out of those states and started vaccinating along the trail that migrants followed.

It worked. By 2009, 741 cases of polio were reported in India, says Thacker. By 2010, that number dropped to 42, and by 2011, only one case — as of today, India’s last — was reported in the entire country. Today, officially 71% of children in India are immunized against polio, with 98% of children in the highest-risk areas having been immunized. In the process, the National Polio Surveillance Project became India’s most extensive public-health surveillance system. There are currently 27,000 reporting units across the country, run through a combination of funding from the government, WHO, UNICEF, the Bill & Melinda Gates Foundation and the CDC, among other groups. India has become one of the world’s largest donors to global polio eradication, putting billions of dollars into fighting the disease at home and also lending its hard-won expertise to Pakistan, Afghanistan and Nigeria, where the virus is still being actively transmitted. (Here’s a graphic of how the global polio program is funded.)

Members of the national surveillance team have gone to Nigeria and Pakistan in particular to help those countries set up similar systems. It’s an especially complicated task in Pakistan, where the effort to immunize children has become highly politicized, as anti-Western hard-liners have scared parents in high-risk areas into refusing the vaccine by spreading rumors about its safety and, worse, by attacking the vaccinators themselves. In December, the murder of nine health care workers during a polio-vaccine drive was linked to the Pakistani Taliban. It’s part of what makes this stage of the fight against polio — so tantalizingly close to being over — such a crucial one. As TIME’s Jeffrey Kluger wrote in a recent story on polio and politics: “All viruses fight back against their eradication. Polio is the only one with a propaganda wing and an armed militia on its side.”

The wisdom gained during the long years of hard work in India will not go to waste there. Infectious diseases like tuberculosis could benefit hugely from the kind of political will and national coordination that the government has shown in fighting polio. The infrastructure of the national surveillance project is already being used to deliver other health services to people living in hard-to-reach parts of the country.

Whatever the disease, it’s people like Ramesh Ferris who can do the most to persuade the public to take action. Last July, he went to Karachi to help educate parents about polio immunization. He climbed six flights of stairs on his crutches to reach a family on the top floor and show them firsthand the risk to which they are exposing their kids by refusing to let them get the vaccine. After a long, tense moment, the family opened the door and let him in, and Ferris personally administered the vaccine. “We have invested so much time and money into this fight. We can’t let hostility and misconceptions veer off our journey,” he says.

In India, too, Ferris cautions that the fight isn’t over just because the country has gone two years without new transmissions. “There is something called the polio endgame,” says Thacker. “You have a war, and once you declare the war is over, you take your weapons back and just survey.” India isn’t there yet. Children need to keep getting vaccines, and surveillance can’t stop, especially with a neighboring country in which the disease is still on the move. Says Ferris: “We’re not out of the woods yet.”